The present invention relates to arm and fuze switching systems of unguided ballistic missiles. In keeping with advancements of ballistic missile countermeasure technology, considerable research and development effort has been directed toward increasing the capability of ballistic missile arm and fuze switching systems to withstand the effects of such countermeasures. Two intended reliability improvements of one such switching system were the self-setting mechanical timer disclosed in U.S. Pat. No. 3,614,465 and the two-level drag switch designed to control the functions of the mechanical timer and disclosed in U.S. Pat. No. 3,715,535. These two devices were developed for the purpose of redundantly, with the highly-accurate pre-launch programmable electric timer, turning on the radar. However, these devices have been found unsatisfactory in improving reliability of the arm and fuze switching system in that the mechanical timer takes precedence over the electric timer and turns on the radar at abnormally high elevations in most missile trajectories to substantially increase the warhead's vulnerability to radar-aided countermeasures.
Considerable effort has also been directed toward the problem of electronically fail safing ballistic missile arming and fuzing systems against premature actuation and actuation in response to countermeasure proximity blast effects. A result of this effort was development of the fluid metering and single integrating drag switch disclosed in my U.S. Pat. No. 3,909,569. This fail safing or arming switch principle, in turn, made possible the invention "Mechanical Ballistic Missile Near Surface Fuzing Switches", disclosed in my U.S. patent application Ser. No. 345,068, filed on Feb. 2, 1982.
The present invention relates directly to that of Ser. No. 345,068 in that it eliminates the roller band mechanism and the need for flow compensation of the metering fluid of the arming switch, otherwise required because of temperature-caused variance of the viscosity of the switch's metering fluid. These simplifications, in turn, permit the present invention to be housed in a single cylindrical case rather than the original two cases.
In comparison with representative conventional unguided ballistic missile arming and fuzing systems requiring an electric timer, a radar and several ancillary components, the present invention reduces space requirements by approximately 50 percent, reduces cost by an estimated 80 percent, overcomes susceptibility to premature switching attendant to high elevation proximity blast and radar-aided countermeasures, and insures minimal near surface fuzing elevation errors in both perturbed and unperturbed missile missions.